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and  Celestial 


277 
J83 
1885 
NMAH 


deSLiN'S   HAND-B00K 


317 
cTS3 


HOW   TO    USE   A   GLOBE. 


JOSLIN'S 


TERRESTRIAL  AND  CELESTIAL 


GLOBES. 


AUG_0^JS91 

i/BRARlES 


GILMAN   JOSLIN    &    SON, 

Manufacturers  and  Dealers,  5  Mt.  Vernon  Ave., 
BOSTON,   MASS. 


USEFULNESS   OF  GLOBES. 


The  importance  of  globes,  both  as  articles  of  school  and 
household  furniture,  has  long  been  greatly  under-estimated. 

Until  within  a  few  years  they  were  to  be  found,  with  rare 
exceptions,  only  among  our  colleges  and  leading  academies, 
with  occasionally  one  in  some  public  or  private  library,  and 
were  regarded  almost  in  the  light  of  a  curiosity  by  the  large 
mass  of  people. 

In  these  days  of  popular  education,  however,  the  import- 
ance and  necessity  of  their  use  in  framing  correct  ideas  in  the 
minds  of  children  at  the  outset,  together  with  their  value  for 
subsequent  reference  and  study,  has  become  much  more 
widely  recognized,  and  has  led  to  their  general  introduction 
into  schools  of  all  grades. 

It  is  an  important  fact  in  favor  of  such  general  introduction 
that  almost  all  children  and  many  grown  people  manifest 
intense  interest  and  surprise  when  they  see  a  globe  for  the 
first  time.  They  then  seem  to  drink  in  at  once  an  entirely 
new  idea  of  the  correct  shapes  and  true  relative  positions  of 
the  various  countries,  their  false  notions  of  which  have  been 
produced  by  the  exclusive  study  of  maps  printed  on  flat  sur- 
faces, and  which  are,  on  that  account,  necessarily  somewhat 
incorrect. 

As  a  matter  of  fact,  the  presence  of  a  globe  in  the  school- 
room, even  though  not  a  single  lesson  be  given  upon  it,  has 
been  found  to  be  of  the  greatest  assistance ;  for,  having  it 
constantly  before  them,  the  scholars  acquire  many  and  cor- 
rect ideas  which  could  not  be  gathered  from  books,  the  im- 


4  JOSLINS   GLOBES. 

p  cessions  from  which  are  of  valuable  and  lasting  service  to 
them. 

As  an  example  of  the  increased  consideration  now  being 
given  to  this  subject,  we  may  say  that  the  City  of  Boston, 
whose  schools  are  universally  conceded  to  be  among  the  fore- 
most in  this  country,  has  recently  purchased  for  their  use 
one  or  more  of  Joslins  Globes  for  every  school-room  above  the 
primary  grade  throughout  the  city.  Moreover,  the  Joslin 
Globe  was  selected  after  a  critical  examination  by  the  Com- 
mittee of  all  globes  in  the  market. 

For  library  or  office  use  a  globe  is  no  less  valuable,  showing, 
as  it  does  at  a  glance,  the  true  relative  situations  of  Political 
and  Geographical  Divisions,  Cities,  etc.,  the  world  over. 

Some  of  the  advantages  of  these  globes  are :  They  may  be 
depended  upon  as  accurate,  the  plates  having  lately  been 
revised  to  correspond  with  all  recent  political  changes.  All 
the  maps  are  printed  directly  from  copper  plates,  and  are  not 
lithographed.  The  meridians  are  accurately  graduated.  The 
varnish  is  warranted  not  to  crack  or  peel  off,  a  common  failing. 
The  stands  are  thoroughly  and  firmly  fitted  together,  and  the 
general  workmanship  throughout  is  of  the  first  order. 

Finally,  it  will  be  our  constant  endeavor  to  maintain  the 
reputation  which  our  globes  have  long  enjoyed  for  superior 
accuracy,  durability,  and  beauty,  and  to  merit  on  that  account 
a  liberal  share  of  public  patronage. 

With  these  few  introductory  remarks  upon  the  general 
usefulness  and  importance  of  the  globe,  we  will  proceed  to 
describe  how  to  use  a  globe  in  the  working  of  problems,  etc. 

GILMAN  JOSLIN  &  SON. 


JOSLINS   GLOBES. 


HOW  TO  USE  A  GLOBE. 


1.  A  Terrestrial  Globe  is  a  ball  or  sphere,  representing  the 
earth.  Upon  its  surface  are  drawn  the  natural  divisions  of 
land  and  water,  —  continents,  islands,  capes,  mountains, 
oceans,  lakes,  bays,  rivers,  etc. ;  it  also  represents  the  political 
•divisions  of  countries,  and  the  lines  of  latitude  and  longitude. 

2.  The  Axis  of  the  earth  is  represented  by  the  iron  rod 
which  passes  through  the  centre  of  the  globe,  and  upon  which 
it  turns. 

3.  The  Poles  of  the  earth  are  the  two  ends  of  the  axis ;  one 
is  called  the  North  or  Arctic  Pole,  and  the  other  the  South 
or  Antarctic  Pole. 

4.  The  Equator  is  a  circle  passing  around  the  globe  at  equal 
distances  from  the  poles.  It  divides  the  globe  into  the  North- 
ern and  Southern  hemispheres. 

5.  The  Equinoctial  is  the  equator  extended  to  the  heavens. 
When  the  sun  is  crossing  the  equinoctial,  the  days  and  nights 
are  equal  all  over  the  world. 

6.  All  Circles  on  the  globe  are  supposed  to  be  divided  into 
360  equal  parts,  called  degrees. 

7.  The  Brass  Meridian  is  the  circle  of  brass  within  which 
the  globe  turns  on  its  axis.  One  half  of  this  meridian  is 
graduated  from  the  equator  to  the  poles;  that  is,  the  point 
over  the  equator  is  0,  and  the  point  over  the  poles  is  90 ;  this 
enables  us  to  find  the  latitude  of  a  place.  The  other  half  is 
from  0  at  the  poles  to  90  at  the  equator ;  this  is  so  that  we 
can  elevate  the  pole  to  the  latitude  of  the  place. 

8.  Meridians  of  longitude  are  semicircles  extending  from 
pole  to  pole,  and  cut  the  equator  at  right  angles.  Beginning 
at  Greenwich,  which  is  called  the  first  meridian,  there  is  on 
the  globe  a  meridian  every  15  degrees ;  these  correspond  to 
the  hours  of  time,  dividing  the  globe  into  24  equal  parts. 


6  joslin's  globes. 

9.  The  Longitude  of  a  place  is  the  distance  of  the  meridian 
passing  through  it  from  the  first  meridian,  reckoned  in  degrees 
on  the  equator.  Longitude  is  either  east  or  west,  according 
as  the  place  is  east  or  west  of  the  first  meridian.  The  figures 
on  the  north  side  of  the  equator  express  the  degrees  of  longi- 
tude, and  are  reckoned  from  Greenwich  east  and  west  from  0° 
to  180°.  The  Roman  letters  on  the  south  side  of  the  equator 
represent  the  hours  of  time,  and  correspond  to  the  degrees 
of  longitude.  The  figures  between  the  letters  express  the 
minutes  of  time.  The  edge  of  the  brass  meridian  is  used  for 
drawing  a  meridian  through  any  place. 

10.  Parallels  of  Latitude  are  small  circles  parallel  to  the 
equator,  and  on  the  globe  are  drawn  at  distances  of  10  degrees 
from  each  other. 

11.  The  Latitude  of  a  place  is  its  distance  north  or  south 
of  the  equator,  reckoned  in  degrees  on  the  brass  meridian. 

12.  Parallels  of  Celestial  Latitude  are  small  circles  drawn  on 
the  celestial  globe  parallel  to  the  ecliptic. 

13.  Parallels  of  Declination  are  small  circles  parallel  to  the 
equinoctial  on  the  celestial  globe,  and  are  similar  to  parallels 
of  latitude  on  a  terrestrial  globe. 

14.  The  Tropics  are  two  small  circles  parallel  to  the  equator, 
23  2  degrees  from  it.  The  northern  is  called  the  Tropic  of 
Cancer,  and  the  southern  the  Tropic  of  Capricorn. 

15.  The  Polar  Circles  are  two  small  circles  parallel  to  the 
equator,  and  23 2  degrees  from  the  poles.  The  northern  is 
the  Arctic  circle,  and  the  southern  is  the  Antarctic. 

16.  The  Zones.  The  surface  of  the  earth  is  divided  by  the 
tropics  and  polar  circles  into  five  parts,  called  zones.  The 
part  lying  between  the  tropics  of  Cancer  and  Capricorn  is 
called  the  Torrid  Zone ;  between  the  tropic  of  Cancer  and  the 
Arctic  circle,  the  North  Temperate  Zone ;  between  the  tropic 
of  Capricorn  and  the  Antarctic  circle,  the  South  Temperate 


JOSLIN  S   GLOBES.  7 

Zone;  between  the  Arctic  circle  and  the  North  pole,  the 
North  Frigid  Zone ;  between  the  Antarctic  circle  and  the 
South  pole,  the  South  Frigid  Zone. 

17.  The  Ecliptic  is  a  great  circle  representing  the  sun's 
apparent  path  throughout  the  year.  It  touches  the  tropics  of 
Cancer  and  Capricorn,  and  is  inclined  to  the  equator  at  an 
angle  of  23 1  degrees.  The  two  points  where  it  crosses  the 
equator  are  called  the  Equinoctial  Points. 

18.  The  Signs  of  the  Zodiac.  The  ecliptic  is  divided  into 
twelve  parts  of  30  degrees  each,  called  Signs  of  the  Zodiac, 
each  having  a  particular  name  and  character  by  which  it  is 
designated.  There  are  six  northern  and  six  southern  ones. 
The  sun  appears  in  the  former  in  our  spring  and  summer 
months,  and  in  the  latter  during  our  autumn  and  winter 
months.  The  days  on  which  the  sun  enters  the  different  signs 
are  as  follows  :  — 

Northern  Signs  of  the  Zodiac 
Spring  Signs.  Summer  Signs. 

Aries,  the  Ram,  March  21.  Cancer,  the  Crab,  June  21. 

Taurus,  the  Bull,  April  20.  Leo,  the  Lion,  July  23. 

Gemini,  the  Twins,  May  21.  Virgo,  the  Virgin,  August  23. 

Southern  Signs  of  the  Zodiac. 
Autumnal  Signs.  Winter  Signs. 

Libra,  the  Balance,  Sept.  23.  Capricornus,  the  Goat,  Dec.  22. 

Scorpio,  the  Scorpion,  Oct.  23.  Aquarius,  the  Waterman,  Jan.  20. 

Sagittarius,  the  Archer,  Nov.  23.       Pisces,  the  Fishes,  Feb.  19. 

19.  The  Equinoctial  Points  where  the  equator  crosses  the 
ecliptic  are  Aries  and  Libra  ;  the  former  is  the  Vernal  and 
the  latter  the  Autumnal  equinox.  When  the  sun  is  in  either 
of  these  points,  the  days  and  nights  are  equal  all  over  the 
world. 

20.  The  Solstitial  Points  are  the  points  where  the  ecliptic 
touches  the  tropics  of  Cancer  and  Capricorn.     When  the  sun 


8 


enters  Cancer,  it  is  the  longest  day  in  the  northern  and  the 
shortest  in  the  southern  hemisphere.  On  the  contrary,  when 
the  sun  enters  Capricorn,  it  is  the  shortest  day  in  the  northern 
and  the  longest  in  the  southern  hemisphere. 

21.  The  Comres  are  two  great  circles  passing  through  the 
poles.  The  equinoctial  colure  passes  through  the  equinoctial 
points ;  the  other,  the  solstitial  colure,  passes  through  the 
solstitial  points. 

22.  The  Zenith  is  the  point  in  the  heavens  directly  over 
our  heads. 

23.  The  Nadir  is  the  point  in  the  heavens  directly  below 
our  feet. 

24.  Antipodes  are  the  people  who  live  on  opposite  sides  of 
the  earth,  and  walk  feet  to  feet.  Their  latitudes,  longitudes, 
days  and  nights,  seasons,  are  exactly  contrary  to  each  other. 

25.  There  are  two  Horizons ;  the  sensible  or  visible  horizon, 
and  the  rational  or  true  horizon. 

26.  The  Sensible  Horizon  is  that  circle  in  the  earth  which 
bounds  our  view. 

27.  The  Kational  or  True  Horizon  is  a  great  circle  of  the 
heavens,  everywhere  90  degrees  from  the  zenith. 

28.  The  Altitude  of  an  object  in  the  heavens  is  its  distance 
from  the  horizon.  When  the  body  is  on  a  meridian,  such  as 
the  sun  at  noon,  its  altitude  is  then  called  meridian  altitude. 

29.  The  Zenith  Distance  of  a  celestial  body  is  its  distance 
from  the  zenith. 

30.  The  Quadrant  is  a  thin,  flexible  strip  of  brass,  divided 
upward  from  0  to  90  degrees,  and  downward  from  0  to  18 
degrees.  It  can  be  screwed  to  the  brass  meridian.  The 
upper  part  is  used  for  finding  distances  between  places  on  the 
earth,  the  altitude  of  heavenly  bodies,  etc.,  and  the  lower  for 
finding  the  length  of  twilight. 

31.  Almacanters  or  Parallels  of  Altitude  are  imaginary  circles 


joslin's  globes.  9 

parallel  to  the  horizon,  and  serve  to  show  the  height  of  the 
sun,  moon,  and  stars.  The  circles  are  not  drawn  on  the  globe, 
but  they  may  be  described  for  any  latitude  by  the  quadrant 
of  altitude. 

32.  Azimuth  or  Vertical  Circles  are  great  circles  passing 
through  the  zenith  and  nadir  points,  cutting  the  horizon  at  right 
angles.  The  altitudes  of  the  heavenly  bodies  are  measured 
on  these  circles.  This  is  done  by  screwing  the  quadrant  of 
altitude  on  the  zenith  of  the  place  of  observation,  and  moving 
the  slip  of  brass  until  its  graduated  edge  passes  through  the 
body. 

33.  The  Azimuth  of  any  celestial  body  is  an  arc  of  the 
horizon  lying  between  a  vertical  circle  passing  through  the 
body  and  the  north  or  south  points  of  the  horizon. 

34.  The  Amplitude  of  any  celestial  body  is  the  distance 
at  which  it  rises  from  the  east  or  sets  from  the  west. 

35.  The  Wooden  Horizon,  surrounding  the  artificial  globe, 
represents  the  rational  horizon.  It  is  usually  divided  into 
seven  concentric  circles :  the  first  is  for  finding  the  amplitude 
of  heavenly  bodies ;  the  second  for  finding  their  azimuth; 
the  third  contains  the  thirty-two  points  of  the  compass;  the 
fourth  contains  the  twelve  signs  of  the  zodiac,  with  the  degrees 
of  each  sign ;  the  fifth  contains  the  days  of  the  month,  corre- 
sponding to  every  degree  of  the  sun's  place  in  the  ecliptic, 
as  indicated  in  the  fourth  circle  ;  the  sixth  contains  the  equa- 
tion of  time,  that  is,  the  difference  of  time  between  a  clock 
and  a  sun-dial;  the  seventh  contains  the  twelve  calendar 
months. 

36.  The  Hour  Circle  is  a  flat  brass  circle  turning  on  the 
axis  of  the  globe  at  the  pole,  and  under  the  brass  meridian. 
It  is  divided  into  24  equal  parts  representing  hours.  It  is 
used  for  finding  the  difference  of  time  between  places,  the 
length  of  the  days,  etc.     On  some  globes  the  hour  circle  is. 


10  joslin's  globes. 

drawn    around    the   pole,  and   has  a  brass    index  which   is 
attached  to  the  axis. 

37.  The  Declination  of  the  sun  is  its  distance  north  or  south 
of  the  equinoctial.  At  the  equinoxes  it  has  no  declination. 
At  the  tropic  of  Cancer  it  has  its  greatest  northern  declination, 
and  at  the  tropic  of  Capricorn,  its  greatest  southern  declination. 

38.  The  Eight  Ascension  of  the  sun  is  the  distance  of  the 
meridian  passing  through  the  sun's  place  in  the  ecliptic,  from 
the  equinoctial  point  Aries,  reckoned  in  degrees  eastward 
on  the  equator  or  equinoctial. 

39.  The  Analemma  is  a  diagram  resembling  the  figure  8. 
It  is  a  scale  drawn  on  the  terrestrial  globe  from  one  tropic  to 
the  other,  showing  the  sun's  declination  on  any  day  in  the 
year.  It  contains  the  months  and  days  and  signs  of  the 
zodiac,  and  shows  the  equation  of  time,  that  is,  the  difference 
between  clock-time  and  that  of  the  sun-dial. 


PKOBLEMS  ON  THE  TERKESTKIAL  GLOBE. 

Problem  I.  To  find  the  latitude  and  longitude  of  any 
given  place. 

Rule.  Bring  the  given  place  to  the  graduated  edge  of  the  metallic 
meridian  ;  the  degree  directly  over  the  place  is  the  latitude.  The  degree 
on  the  equator  cut  by  the  metallic  meridian  is  the  longitude. 

EXAMPLES. 

What  is  the  latitude  and  longitude  of  the  following  places? 

New  York.  Answer:  Lat.  41°  N.     Long.  74°  W. 

San  Francisco.  " 

Calcutta. 

Rio  Janeiro.  " 

Quito. 


37°  N. 

"    122°  W. 

23°  N. 

"      89°  E. 

23°  S. 

"      43°  W. 

0° 

"      79°  W. 

joslin's  globes.  11 

The  latitude  of  the  north  and  of  the  south  pole  is  90°. 
The  longitude  of  the  poles  is  0°.  90°  is  the  highest  latitude 
that  any  place  can  have.  180°  is  the  highest  longitude  that 
any  place  can  have.  All  places  on  the  equator  have  no 
latitude.     All  places  on  the  first  meridian  have  no  longitude. 

Problem  II.  To  find  any  place  on  the  globe  having  its 
latitude  and  longitude  given. 

Rule.  Find  the  given  longitude  on  the  equator,  and  bring  it  to  the 
metallic  meridian.  Find  the  given  latitude  on  the  metallic  meridian, 
and  the  place  immediately  under  will  be  the  place  required. 

EXAMPLES. 
What  places  have  about  the  following  latitudes  and  longi- 
tudes? 


33°  S. 

72°  W. 

Answer 

:  Valparaiso. 

9°N. 

80°  W. 

" 

Panama. 

42°  N. 

88°  W. 

" 

Chicago. 

19°  N. 

100°  w. 

u 

Mexico. 

35°  N. 

140°  E. 

(( 

Yokohama. 

Problem  III.  To  find  all  those  places  which  have  the 
same  latitude  as  a  given  place. 

Rule.  Bring  the  given  place  to  the  metallic  meridian,  and  find  its 
latitude.  Turn  the  globe  slowly  round,  and  all  places  which  pass  under 
the  observed  latitude  will  be  the  ones  required. 

EXAMPLES. 
What  places  have  about  the  same  latitude  as  Boston  ? 

Answer:    Albany,   Buffalo,   Chicago,   Omaha,   Constanti- 
nople, Rome,  Marseilles. 

All  places  in  the  same  latitude  have  the  same  seasons  and 
the   same   length   of  day  and   night ;  but,   owing  to  various 


12  joslin's  globes. 

physical  causes  (such  as  the  adjoining  land  and  water),  they 
may  not  have  the  same  climate. 

Problem  IV.  To  find  all  those  places  which  have  the 
same  longitude  as  a  given  place. 

Rule.  Bring  the  place  to  the  metallic  meridian.  All  places  under 
the  edge  of  the  metallic  meridian,  from  pole  to  pole,  have  the  same 
longitude. 

People  living  in  the  same  longitude  have  noon  and  all  of 
the  hours  of  the  day  alike ;  their  clocks  all  agree ;  but  they 
all  have  sunrise  and  sunset  at  different  hours  from  one 
another,  depending  on  their  latitude. 

EXAMPLES. 

What  places  have  about  the  same  longitude  as  Copenhagen  ? 
Answer :  Berlin,  Venice,  Rome,  Palermo,  Tripoli,  mouth 
of  the  Congo  River. 

What  people  have  nearly  the  same  time  as  the  people  of 
Massachusetts  ? 

Answer:  Those  in  Quebec,  Hayti,  Venezuela,  Colombia, 
Ecuador,  Peru,  and  Chili. 

Problem  V.     To  find  the  distance  between  two  places. 

Rule.  Lay  the  edge  of  the  quadrant  of  altitude  over  the  two  places, 
so  that  the  point  marked  0  may  be  over  one  of  them;  the  number  of 
degrees  over  the  other  place  will  be  the  number  of  degrees  they  are 
apart.  Multiply  the  number  of  degrees  by  60  for  the  geographical  miles, 
or  by  69&  for  the  English  or  statute  miles.  Or  take  the  distance  between 
the  two  places  with  a  thread ;  apply  that  distance  to  the  equator ;  this 
will  show  the  number  of  degrees  in  the  distance ;  then  multiply  as  before 
for  the  miles. 


joslin's  globes.  13 

examples. 
What  is  the  distance  between 

Degrees.    Geog.  Miles.      Eng.  Miles. 

Portland  and  San  Francisco  ?     Answer :  39 \      2370       2732 
London      "    Constantinople?  "         22        1320       1522 

Liverpool  "    Cairo?  "         34       2040       2352 

Problem  VI.  The  hour  of  the  day  being  given  at  one 
place,  to  find  what  hour  it  is  at  any  other  place. 

Rule.  Bring  the  place  at  which  the  time  is  given  to  the  metallic 
meridian  ;  turn  the  hour  circle  until  the  given  hour  comes  to  the  metallic 
meridian,  or  set  the  hour  index  to  the  given  hour  ;  turn  the  globe  until 
the  other  place  comes  under  the  metallic  meridian,  and  the  hour  on  the 
hour  circle,  which  is  under  the  metallic  meridian  or  under  the  index, 
will  be  the  time  required. 

Or  thus  by  calculation. 

Rule.  Find  the  difference  in  longitude  between  the  two  places, 
allow  an  hour  for  every  15  degrees  and  4  minutes  for  every  degree,  and 
the  time  thus  obtained  will  be  the  difference  of  time  between  the  two 
places.  If  the  place  at  which  the  time  is  required  lies  to  the  east  of  the 
given  place,  this  difference  of  time  must  be  added  to  find  the  time  at  the 
place  required  ;  but  if  it  lies  to  the  west,  it  must  be  subtracted. 

EXAMPLES. 

When  it  is  3  o'clock  in  the  afternoon  at  London,  what  time 
is  it  at  St.  Petersburgh  ? 

Answer:  5  o'clock  in  the  afternoon. 
Or  by  calculation.  The  difference  in  longitude  is  30° ; 
divided  by  15  gives  just  2  hours  difference  of  time. 
St.  Petersburgh  being  east  of  London,  this  2  hours 
must  be  added  to  the  London  time,  which  gives  us 
5  o'clock  in  the  afternoon. 


14  joslin's  globes. 

When  it  is  2  o'clock  in  the  afternoon  at  Cairo,  what  time  is 
it  at  New  York  ? 

Answer  :  7  o'clock  in  the  morning. 
By  calculation.     Longitude,  Cairo,  31°  E. 

New  York,  74°  W. 

Difference  of  longitude,  105°,    divided    by 
15  gives  7,  the  difference  in  hours. 

New  York  being  west  of  Cairo,  these  7  hours  must  be 
subtracted  from  Cairo  time,  and  7  from  2  o'clock  in  the 
afternoon  is  7  o'clock  in  the  morning. 

Problem  VII.  The  time  of  any  two  places,  and  one  of  the 
places  being  given,  to  find  the  longitude  of  the  other  place. 

Rule.  Bring  the  given  place  to  the  metallic  meridian,  set  the  hour 
index  at  the  given  hour  of  the  place,  turn  the  globe  until  the  other  given 
hour  comes  under  the  metallic  meridian,  and  the  degree  on  the  equator 
cut  by  the  metallic  meridian  will  be  the  longitude. 

Or  by  calculation. 

Rule.  Allow  15°  difference  of  longitude  for  every  hour  of  time,  or 
1°  for  every  4  minutes  of  time. 

EXAMPLES. 

When  it  is  4  o'clock  in  the  afternoon  at  a  certain  place,  it 
is  noon  at  London ;  required  the  longitude  of  the  place. 
Answer :  60°  east  longitude. 

By  calculation.  4  hours  of  time,  at  15°  for  each  hour, 
gives  60°,  the  difference  of  longitude.  As  the  hour  at 
London  is  earlier  than  at  the  other  place,  it  follows 
that  the  place  must  be  60°  to  the  east  of  London ;  or, 
as  London  has  0°  for  longitude,  the  place  must  have 
60°  east  longitude. 


joslin's  globes.  15 

When  it  is  noon  at  Boston,  at  what  places  is  it  10  o'clock 
in  the  morning. 

Answer:  All  places  in  longitude  100°  west,  as  the 
middle  of  Nebraska,  Kansas,  Texas,  and  the  city  of 
Mexico. 

Problem  VIII.  To  find  the  length  of  a  degree  in  any 
given  parallel  of  latitude. 

Rule.  Lay  the  edge  of  the  quadrant  of  altitude  along  the  given 
parallel;  take  the  number  of  degrees  upon  it  intercepted  between  any 
two  meridians  (15°  apart),  and  that  number  multiplied  by  4  will  give 
the  number  of  geographical  miles  contained  in  a  degree  of  the  given 
parallel.  To  find  the  number  of  English  miles,  multiply  the  number  of 
degrees  by  69^,  and  divide  by  15,  or,  what  is  the  same  thing,  multiply 
the  number  of  degrees  by  4.6. 

EXAMPLES. 

How  many  geographical  and  English  miles  are  there  in  a 
degree  on  the  50th  parallel  of  latitude  ? 

Answer :  The  distance  between  two  meridians  15°  apart 
on  the  50th  parallel  is  9f°  of  the  equator. 
9f  X  4     =39       geographical  miles. 
9|  x  4.6  =  44.85  statute  miles. 

What  is  the  length  of  a  degree  on  the  parallel  of  30°  ? 
Answer :  15°  parallel  of  30°  =  13°  on  the  equator. 
13  X  4     =52     geographical  miles. 
13  x  4.6  =  59.8  statute  miles. 


Problem  IX.      To  find  the  Antipodes  of  a  given  place. 

Rule.     Bring  the  given  place  to  the  metallic  meridian  ;  set  the  index 
of  the  hour  circle  at  12,  or  bring  12  on  the  hour  circle  to  the  metallic 


16  joslin's  globes. 

meridian ;  turn  the  globe  half  round,  or  until  the  index  points  to  the 
other  12 ;  then,  under  the  same  degree  of  latitude  with  the  given  place, 
but  in  the  opposite  hemisphere,  will  be  the  place  of  the  Antipodes. 

EXAMPLES. 

Required  the  Antipodes  of  the  following  places :  — 

London.  Answer:  Antipodes  Island,  near  New  Zealand. 

Spain.  "         New  Zealand. 

Chili.  "         China. 

Bermudas  Islands.     "         South-west  part  of  West  Australia. 

Problem  X.      To  "rectify  the  globe  for  any  given  place. 

Rule.  Elevate  or  raise  the  north  or  south  pole  as  many  degrees 
above  the  wooden  horizon  as  are  equal  to  the  latitude  of  the  place,  and 
bring  the  given  place  to  the  metallic  meridian.  If  the  given  place  is  in 
north  latitude,  the  north  pole  must  be  elevated ;  if  in  south  latitude,  the 
south  pole.  In  elevating  either  pole,  the  degrees  must  be  counted  from 
the  pole  to  be  elevated  toward  the  equator. 

EXAMPLES  ' 

Rectify  the  globe  for  Boston. 

Boston  is  in  latitude  42 \°  north;  therefore  elevate  the 
north  pole  42£°  above  the  wooden  horizon,  and  turn  the  globe 
until  Boston  comes  to  the  edge  of  the  metallic  meridian. 

Rectify  the  globe  for  Rio  Janeiro. 

Rio  Janeiro  is  23 j°  south  latitude.  Elevate  the  south  pole 
23 2°  above  the  wooden  horizon,  and  turn  the  globe  until  Rio 
Janeiro  comes  to  the  edge  of  the  metallic  meridian. 

Note.  When  the  globe  is  rectified  for  any  place,  the  place  is  in  the 
zenith  of  the  globe ;  that  is,  it  is  everywhere  90°  from  the  wooden  hori- 
zon, and  the  wooden  horizon  becomes  the  true  horizon  of  the  place. 


joslin's  globes.  17 

Now,  if  the  stand  of  the  globe  is  made  to  occupy  a  horizontal  position, 
and  the  north  and  south  points  of  the  wooden  horizon  are  made  to  cor- 
respond with  the  north  and  south  points  of  the  compass,  the  globe  is 
said  to  be  set.  In  this  position  the  axis  of  the  globe  is  parallel  with  the 
axis  of  the  earth,  the  equator  of  the  globe  to  the  equator  of  the  earth, 
the  parallels  of  the  globe  to  the  parallels  of  the  earth  ;  and  the  globe 
may  be  turned,  so  that  the  ecliptic  on  the  globe  shall  be  parallel  to  the 
ecliptic  in  the  heavens  on  any  day  in  the  year. 


Problem  XI.  To  find  the  suns  place  in  the  ecliptic 
for  any  given  day. 

Rule.  Find  the  month,  and  the  mark  corresponding  to  the  day  of 
that  month,  in  the  outer  circle  of  the  wooden  horizon ;  then  the  coin- 
cident mark  in  the  circle  containing  the  signs  of  the  zodiac  will  give  the 
sun's  place  in  the  ecliptic,  which  may  then  be  found  upon  the  globe. 

In  Joslin's  Globes  the  ecliptic  is  divided  also  into  the  months  and 
the  days  of  the  month,  so  that  any  required  day  may  be  found  directly 
on  the  ecliptic. 


Problem  XII.  To  find  the  suns  declination  for  any  given 
day,  and  also  to  find  the  places  to  which  the  sun  will  be 
vertical  on  that  day. 

Rule.  Find  the  sun's  place  in  the  ecliptic  for  the  given  day  ;  bring 
that  point  in  the  ecliptic  to  the  metallic  meridian,  and  the  degree  directly 
over  it  on  the  metallic  meridian  is  the  declination,  north  or  south.  Turn 
the  globe  around,  and  every  place  which  passes  under  that  degree  of  the 
metallic  meridian  will  have  the  sun  vertical  on  that  day. 

The  declination  of  the  sun  gives  the  latitude  of  the  places  which  will 
have  the  sun  vertical  on  that  day.  The  sun  can  be  vertical  only  to 
places  within  the  torrid  zone. 

Or  the  declination  may  be  found  by  bringing  the  given  day  on  the 
analemma  to  the  metallic  meridian,  and  the  degree  on  the  meridian 
over  the  day  on  the  analemma  will  be  the  declination. 


18  joslin's  globes. 

examples. 

What  is  the  declination  of  the  sun  on  the  21st  of  June,  and 
what  is  the  latitude  of  the  places  that  will  have  the,  sun 
vertical  on  that  day  ? 

Answer:  23 1°  North  Declination. 
23  J°  North  Latitude. 

What  is  the  sun's  declination  on  the  following  days? 
Sept.  12.     Answer:  4J°  North  Declination. 
Dec.  10.  "       22i°  South 

Jan.  1.  "       23°    South 

April  15.  "       10°    North 

Problem  XIII.  To  find  the  hour  at  which  the  sun  rises 
and  sets  at  a  given  place,  for  any  given  day.  Also,  to  find  the 
amplitude  of  the  sun  for  that  day. 

Rule.  Rectify  the  globe  for  the  latitude  of  the  place  by  Problem  X. 
Find  the  sun's  place  in  the  ecliptic,  and  bring  it  to  the  metallic  meridian. 
Set  the  index  of  the  hour  circle  at  12.  Turn  the  globe  until  the  sun's 
place  comes  to  the  eastern  edge  of  the  wooden  horizon,  and  the  index 
will  then  show  the  hour  at  which  the  sun  rises;  then  turn  the  globe 
until  the  sun's  place  comes  to  the  western  edge  of  the  wooden  horizon, 
when  the  index  will  show  the  hour  at  which  the  sun  sets. 

Remark.  1.  The  length  of  the  day  is  found  by  doubling  the  hour 
of  sunset. 

2.  The  length  of  the  night  is  found  by  doubling  the  hour  of  sunrise. 

3.  To  find  the  amplitude  of  the  sun,  observe  the  degree  of  amplitude 
on  the  wooden  horizon,  which  is  cut  by  the  sun's  place  in  the  ecliptic 
at  the  time  of  rising  or  setting. 

EXAMPLES. 

At  what  time  will  the  sun  rise  and  set  at  London  on  the 
21st  of  December?  What  is  the  length  of  the  day  and  night 
at  that  time,  and  what  is  the  amplitude  of  the  sun? 


joslin's  globes.  19 

Answer:  The  sun  rises  at  i  past  8. 
The  sun  sets  at  \  before  4. 
Length  of  day,  7£  hours. 
Length  of  night,  16£  hours. 
Sun's  amplitude,  39°  south  of  east. 

What  is  the  length  of  the  longest  day  at  St.  Petersburgh  ? 
How  far  from  the  east  point  of  the  horizon  does  the  sun  rise 
on  that  day? 

Answer :  Length  of  day,  18?  hours. 

Sun's  amplitude,  52°  north  of  east. 

What  is  the  length  of  the  shortest  day  in  New  York  ? 
Answer :  Length  of  day,  9  hours. 

Show  that  the  day  is  always  12  hours  long  at  the  equator. 

Show  that  the  21st  of  June  is  the  longest  day  to  the  people 
of  the  northern  hemisphere,  and  that  the  21st  of  December 
is  their  shortest. 

Problem  XIV.  To  find  the  suns  meridian  altitude  at  a 
given  place  on  a  given  day. 

Rule.  Rectify  the  globe  for  the  latitude  of  the  place ;  bring  the 
sun's  place  in  the  ecliptic  for  the  given  day  to  the  metallic  meridian ; 
count  the  number  of  degrees  on  the  metallic  meridian,  between  the  sun's 
place  and  the  wooden  horizon,  for  the  meridian  altitude  required. 

Or  thus :  Find  the  declination  of  the  sun  for  the  day,  and  add  to  it 
the  co-latitude  of  the  place  when  the  declination  and  the  co-latitude  are 
of  the  same  name,  but  subtract  it  when  they  are  of  different  names. 

EXAMPLES. 
What  is  the  sun's  meridian  altitude  at  Boston  on  the  21st 
of  June? 

Answer :  71°.     This  is  the  greatest  elevation  of  the  sun 
above  the  horizon  at  Boston. 


20  joslin's  globes. 

By  calculation.     The  latitude  and  declination  are  both 
north.     The  declination  of  the  sun  on  this  day  is  23J° 
north,  and  the  co-latitude  is  90°—  42i°  =  47i°;  there- 
fore the  meridian  altitude  is  23J°  +  47i°  =  71°. 
What  is  the  sun's  meridian  altitude  at  Boston  on  December 
21? 

Answer:  24°.     This  is  the  least  meridian  altitude  of  the 

sun  to  the  people  of  Boston. 
By  calculation.     Here  the  declination  is  south  and  the 
latitude  north,  therefore  we  have  the  meridian  altitude 
47J°-  23J°=24°. 
What  would  be  the  meridian  altitude  of   the  sun  on  the 
21st  of  June  at  the  following  places  ? 
North  Pole.         Answer:  23|°. 
Arctic  Circle.  "  47°. 

Equator.  66 £°,  or  23 i°  from  the  zenith. 

Problem  XV.  To  find  the  suns  altitude  and  azimuth 
at  any  given  place  on  any  given  day  and  hour. 

Rule.  Rectify  the  globe  for  the  latitude  of  the  place ;  bring  the 
sun's  place  in  the  ecliptic  to  the  metallic  meridian ;  set  the  index  at  12 ; 
turn  the  globe  until  the  index  points  to  the  given  hour ;  fix  the  quadrant 
of  altitude  on  the  metallic  meridian,  at  the  degree  of  latitude  of  the 
given  place,  and  lay  its  graduated  edge  over  the  sun's  place ;  then  count 
the  number  of  degrees  on  the  quadrant  between  this  point  and  the  wooden 
horizon,  and  it  will  give  the  altitude  required.  The  number  of  degrees 
on  the  wooden  horizon,  counting  from  the  north  or  south  point  of  it,  to 
the  point  where  the  graduated  edge  of  the  quadrant  cuts  it,  will  be  the 
azimuth. 

EXAMPLES. 

What  is  the  sun's  altitude  and  azimuth  at  London  on  the 
5th  of  May  at  7  o'clock  in  the  morning? 
Answer:  Altitude,  211°. 

Azimuth,  90°  from  the  north. 


joslin's  globes.  21 

What  is  the  sun's  altitude  and  azimuth  at  St.  Petersburgh 
on  July  2  at  4  p.m. 

Answer:  Altitude,  35°. 

Azimuth,  75°  from  the  south. 

Problem  XVI.  The  hour  and  day  at  any  particular 
place  being  given,  to  find  the  place  where  the  sun  is  then 
vertical. 

Rule.  Find  the  sun's  declination  of  the  given  day  (Problem  XII.) ; 
bring  the  given  place  to  the  metallic  meridian  ;  set  the  index  to  the  given 
hour ;  turn  the  globe  until  the  index  points  to  12  noon.  The  place 
under  the  metallic  meridian  whose  latitude  is  the  same  as  the  sun's 
declination  will  have  the  sun  vertical  at  the  hour  given.  This  also 
shows  that  all  places  under  the  metallic  meridian  will  have  noon  at  the 
same  time. 

EXAMPLES. 

To  what   place   will    the   sun  be   vertical  on  the    7th  of 
January  when  it  is  \  to  3  in  the  afternoon  at  London  ? 
Answer :  Rio  Janeiro. 
To  what  place  will  the  sun  be  vertical  when  it  is  2  o'clock 
in  the  afternoon  of  May  15  at  Boston? 
Answer:  City  of  Mexico. 

Problem  XVII.  To  find  the  two  days  in  the  year  in  which 
the  sun  will  be  vertical  to  any  given  place  in  the  torrid  zone. 

Rule.  Bring  the  given  place  to  the  metallic  meridian,  and  observe 
its  latitude.  Bring  the  analemma  to  the  metallic  meridian,  and  the  two 
days  on  it  that  come  under  that  latitude  are  the  days  required. 

EXAMPLES. 
On  what  two  days  of  the  year  will  the  sun  be  vertical  at 
Aspinwall  ? 

Ansiuer :  April  2  and  August  30. 
On  what  two  days  will  the  sun  be  vertical  at  Calcutta  ? 
Answer :  June  10  and  July  4. 


22  joslin's  globes. 

Problem  XVIII.  The  hour  and  day  at  a  particular  place 
being  given,  to  find  the  places  where  the  sun  is  then  rising  or 
setting ;  and  also  places  where  it  is  noon  or  midnight. 

Rule.  Find  the  sun's  declination  for  the  given  day;  elevate  the 
north  or  south  pole  (according  as  the  sun's  declination  is  north  or  south) 
as  many  degrees  above  the  wooden  horizon  as  are  equal  to  the  sun's 
declination ;  bring  the  given  place  to  the  metallic  meridian,  and  set  the 
index  to  the  given  hour ;  turn  the  globe  until  the  index  points  to  12 
noon.  Then  to  all  places  above  the  wooden  horizon  it  will  be  day,  and 
to  all  places  beneath  it  it  will  be  night ;  all  places  on  the  western  edge 
of  the  wooden  horizon  will  have  the  sun  rising,  and  all  places  on  the 
eastern  edge  will  have  it  setting ;  all  places  under  the  upper  half  of  the 
metallic  meridian  will  have  noon,  and  all  those  under  the  lower  half 
will  have  midnight.  All  places  not  more  than  18°  below  the  western 
edge  of  the  horizon  will  have  morning  twilight,  and  all  places  not  more 
than  18°  below  its  eastern  edge  will  have  evening  twilight. 

EXAMPLES. 
When  it  is  8  o'clock  in  the  morning  at  Boston  on  the  23d 
of  June,  where  is  the  sun  rising  and  setting?  and  where  is  it 
noon  and  where  midnight  ? 

Answer:    The   sun  is  rising  at  San  Francisco  and  the 
Pacific  coast  States,  the  southern  part  of  Chili,  and  at 
Patagonia ;  it  is  setting  at  Calcutta,  the  middle  of  th.e 
Chinese  Empire,  and  the  eastern  part  of  Siberia.     It 
is  nearly  noon  at  Ireland,  Portugal,  and  the  extreme 
western  part  of  Africa ;  it  is  midnight  at  the  Loyalty 
Islands  and  New  Zealand. 
When  it  is  4  o'clock  in  the  afternoon  at  London  on  the 
25th  of  April,  where  is  the  sun  rising,  setting,  etc.  ? 
Answer  :  Rising  at  Sandwich  Islands. 

Setting  at  Cape  of  Good  Hope. 

Noon  at  Nova  Scotia,  Venezuela,  and  Buenos 

Ayres. 
Midnight  at  Australia  and  China. 


joslin's  globes.  23 

Problem  XIX.  Any  place  in  the  north  frigid  zone  being 
given,  to  find  how  long  the  sun  shines  there  without  setting,  and 
how  long  he  is  invisible. 

Rule.  Rectify  the  globe  for  the  latitude  of  the  place ;  bring  the 
ascending  signs  of  the  ecliptic  to  the  north  point  of  the  horizon,  and  see 
what  day  of  the  ecliptic  is  cut  by  that  point ;  then  from  that  day  the 
sun  begins  to  shine  without  setting.  Now  bring  the  descending  signs  of 
the  ecliptic  to  the  north  point  of  the  horizon,  and  see  what  day  of  the 
ecliptic  is  cut  by  that  point ;  then  on  that  day  the  sun  ceases  to  shine 
without  setting.  By  proceeding  in  the  same  way  with  the  southern 
point  of  the  horizon,  we  may  find  the  beginning  and  end  of  the  time 
during  which  the  sun  is  invisible. 

EXAMPLES. 

How  long  does  the  sun  shine  without  setting  at  Uppernavik 
in  Greenland,  latitude  72?°  north,  and  how  long  is  he  in- 
visible ? 

Answer:    It  begins  to  shine  continually  on  the  9th  of 
May,  and  ceases  to  shine   continually  on  the  4th  of 
August. 
The  longest  day  is  therefore  87  days  long ;  that  is,  the 

sun  shines  without  setting  for  87  days. 
The  time  during  which  the  sun  will  be  invisible  extends 

from  the  10th  of  November  to  February  1. 
The  longest  night  is  therefore  83  days  long ;  that  is,  the 
sun  is  never  seen  during  this  83  days. 

Problem  XX.  To  find  the  beginning,  end,  and  duration 
of  twilight  at  any  given  place  on  any  given  day. 

Rule.  Rectify  the  globe  for  the  latitude  of  the  place  (Problem  X.) ; 
screw  the  quadrant  of  altitude  upon  the  metallic  meridian  over  the  given 
latitude ;  bring  the  sun's  place  in  the  ecliptic  on  the  given  day  to  the 
metallic  meridian  ;  set  the  hour  circle  at  12 ;  turn  the  globe  westward 
until  the  sun's  place  comes  to  the  western  edge  of  the  wooden  horizon ; 


24  joslin's  globes. 

then  the  hour  circle  "will  show  the  time  of  the  sun's  setting  and  the 
beginning  of  evening  twilight.  Continue  turning  the  globe  until  the 
sun's  place  is  18°  below  the  horizon,  measured  on  the  quadrant  of  alti- 
tude ;  then  the  hour  circle  will  show  the  time  at  which  the  evening 
twilight  ends.  The  duration  of  twilight  is  equal  to  the  difference  between 
the  time  at  which  it  begins  and  the  time  at  which  it  ends. 

The  time  at  which  evening  twilight  ends,  subtracted  from  12,  will 
give  the  time  of  the  beginning  of  morning  twilight,  which  is  of  the 
same  length  as  evening  twilight. 

EXAMPLES. 

Required  the  beginning,  end,  and  duration  of  evening  and 
morning  twilight  at  London  on  the  23d  of  September. 

Answer:  Evening  twilight  begins  at  6  o'clock  and  ends 
at  8  o'clock;  duration,  2  hours.  Morning  twilight 
begins  at  4  o'clock  and  ends  at  6  o'clock. 

Solution:  Evening  twilight  ends        8  h. 
"  "        begins 

Duration  of  twilight 

Evening  twilight  ends 

Morning  twilight  begins 
Duration  of  twilight 

Morning  twilight  ends        6  h. 

Required  the  duration  of  twilight  at  Boston  on  June  1. 
Ansiver :  2|  hours. 

Problem  XXI.  The  suns  meridian  altitude  and  the  day 
of  the  month  being  given,  to  find  the  latitude  of  the  place. 

Rule.  Bring  the  sun's  place  in  the  ecliptic  to  the  metallic  meridian  ; 
then,  if  the  sun  was  south  of  the  observer  when  the  altitude  was  taken, 


6h. 

2h. 

12  h. 

8h. 

4h. 

2h. 

joslin's  globes.  25 

elevate  the  sun's  place  as  many  degrees  above  the  south  point  of  the 
wooden  horizon  as  are  equal  to  the  sun's  meridian  altitude  ;  the  eleva- 
tion of  the  north  pole  above  the  horizon  will  give  the  latitude  of  the 
place.  If  the  sun  was  north  of  the  observer  when  the  altitude  was 
taken,  elevate  the  sun's  place  as  many  degrees  above  the  north  point  of 
the  horizon  as  are  equal  to  the  sun's  meridian  altitude ;  the  elevation  of 
the  south  pole  will  give  the  latitude  of  the  place. 

EXAMPLES. 

On  the  21st  of  June  the  meridian  altitude  of  the  sun  was 
observed  to  be  69  i°,  and  south  of  the  observer ;  what  was  the 
latitude  of  the  place  ? 
Answer :  44°  north. 

December  21  the  meridian  altitude  of  the  sun  was  25°, 
and  south  of  the  observer ;  what  was  the  latitude  of  the 
place  ? 

Answer :  41  f°  north. 

May  10  the  sun's  meridian  altitude  was  observed  to  be 
30°  north  of  the  observer ;  what  was  the  latitude  of  the 
place  ? 

Answer :  42?°  south. 


Problem  XXII.  To  find  all  places  at  which  a  solar  or 
lunar  eclipse  is  visible  at  the  same  instant,  the  day  and  hour 
being  given  when  it  is  visible  at  a  certain  place. 

Rule.  Find  the  place  to  which  the  sun  is  vertical  at  the  given  time ; 
bring  the  place  to  the  metallic  meridian,  and  rectify  the  globe  to  the 
latitude  of  that  place ;  then  at  all  places  within  TO0  of  this  place  an 
eclipse  of  the  sun  may  be  visible,  especially  if  it  be  a  total  eclipse.  If 
it  be  a  lunar  eclipse,  it  will  be  visible  to  all  those  places  below  the 
wooden  horizon. 


26  joslin's  globes. 

EXAMPLES. 

There  was  an  eclipse  of  the  sun  October  9,  1847,  at  7% 
o'clock  in  the  morning,  at  London ;  at  what  places  might  it 
be  visible  ? 

Answer:  London,  Hindoostan,  Arabia,  Egypt,  etc. 

There  was  an  eclipse  of  the  moon  January  26,  1842,  at 
6  o'clock  in  the  afternoon,  at  London ;  at  what  places  was  it 
visible  ? 

Answer:    Europe,    Africa,    part    of    Asia,    and    South 
America. 

There  was  an  eclipse  of  the  moon  January  7,  1852,  at  6 i 
o'clock  in  the  morning,  at  London ;  at  what  places  was  it 
visible  ? 

Answer :    England,    France,    Spain,    North    and    South 
America. 


Problem  XXIII.  To  place  the  terrestrial  globe  in  the 
sunshine  at  any  given  place,  so  that  it  will  represent  the  actual 
position  of  the  earth  at  that  time  with  respect  to  the  sun. 

Rule.  Place  the  globe  so  that  the  wooden  horizon  shall  be  in  a 
horizontal  position,  and  its  north  and  south  points  in  a  line  exactly 
north  and  south,  the  north  to  the  north ;  bring  the  given  place  to  the 
metallic  meridian,  and  rectify  the  globe  to  its  latitude.  All  the  lines 
on  the  globe  are  then  in  the  position  described  under  Problem  X. 

Problem  XXIV.  To  construct  a  horizontal  sun-dial  by 
the  globe  for  any  given  latitude. 

Rule.  Set  the  globe  as  in  Problem  XXII.,  and  bring  the  first  point 
of  Aries  (the  meridian  of  Greenwich)  to  the  metallic  meridian.  Prepare 
a  smooth  board  about  6  inches  wider  than  the  diameter  of  the  globe. 
On  this  board  describe  a  circle  whose  diameter  is  exactly  the  same  as 


joslin's  globes.  27 

the  diameter  of  the  globe.  At  the  extremities  of  a  diameter  of  this  circle 
mark  a  north  and  south  point.  Regard  these  two  points  as  cut  by  the 
plane  of  the  first  meridian.  Mark  the  north  point  12,  which  will  indi- 
cate the  hour  of  noon.  With  a  pair  of  dividers  take  the  exact  distances 
between  each  two  meridians,  15°  apart,  at  the  points  where  they  are 
cut  by  the  horizon,  beginning  at  the  north  point  of  the  horizon  and 
going  each  way.  Transfer  these  distances  to  the  circumference  of  the 
circle  on  the  board,  making  a  point  to  correspond  with  each  meridian. 
Number  the  points  from  12  toward  the  west  11-10-9  for  the  morning 
hours,  and  toward  the  east  1-2-3-4-5  for  the  evening  hours.  No  more 
points  may  be  made  than  equal  the  number  of  hours  in  the  longest  day 
at  the  given  place.  From  the  centre  of  the  circle  draw  a  radius  to  each 
point  in  the  circumference.  In  the  centre  fix  a  pin  inclined  toward  the 
north  point,  or  12,  as  many  degrees  as  are  equal  to  the  latitude  of  the 
place,  and  of  such  length  that  its  shortest  shadow  will  reach  the  cir- 
cumference. This  board  placed  exactly  horizontal  in  the  sunshine,  with 
its  north  and  south  points  in  a  line  exactly  north  and  south,  will  con- 
stitute a  horizontal  sun-dial. 


Problem  XXV.  To  illustrate  the  three  positions  of  the 
sphere,  Right,  Parallel,  and  Oblique,  so  as  to  show  the 
aspect  of  the  sun,  etc.,  at  different  times  of  the  year. 

The  Eight  Sphere.  The  people  at  the  equator  have  this 
sphere  ;  the  north,  polar  star  always  appears  in  their  horizon. 
To  place  the  globe  in  this  position  bring  the  two  poles  to  the 
wooden  horizon  ;  turn  the  globe  round ;  then  the  following 
facts  may  be  readily  shown.  At  the  equator  the  days  are 
always  12  hours  long,  whatever  may  be  the  position  of  the 
sun  in  the  ecliptic ;  for  the  sun  and  all  the  heavenly  bodies 
will  appear  to  revolve  round  the  earth  in  circles  parallel  to 
the  equinoctial,  and  the  diurnal  arc  above  the  horizon  will 
always  be  equal  to  that  which  is  below  it.  The  whole  of  the 
heavens  may  be  seen  at  the  equator  in  the  course  of  the  day, 
and  in  a  year  all  the  stars  in  the  heavens  may  be  seen. 


28  joslin's  globes. 

The  Parallel  Sphere.  The  people  at  the  poles,  if  there  were 
any,  would  have  this  sphere ;  at  the  north  pole,  the  north 
polar  star  would  appear  exactly  overhead.  To  place  the 
globe  in  this  position,  elevate  the  north  pole  90°  above  the 
horizon,  or,  what  is  the  same  thing,  make  the  equator  to 
coincide  with  the  wooden  horizon.  At  the  poles,  during  six 
months  of  the  year,  the-  sun  shines  without  setting,  and  during 
the  other  six  months  he  never  appears  above  the  horizon. 
At  the  poles  the  heavenly  bodies  appear  to  move  in  circles 
parallel  to  the  horizon  ;  they  appear  to  move  entirely  around 
it  every  24  hours.  The  sun  appears  to  move  in  the  form  of 
a  spiral,  higher  each  day,  for  three  months,  till  he  reaches 
his  greatest  declination ;  and  then,  in  a  similar  manner,  lower 
and  lower,  for  three  months,  till  he  goes  below  the  horizon. 
But  there  will  be  twilight  until  the  sun  is  18°  below  the 
horizon.  At  the  poles  an  observer  can  see  only  those  stars 
that  are  in  his  hemisphere.  Near  the  poles  the  stars  do  not 
set,  but  appear  to  revolve  around  the  pole,  going  down  each 
day  toward  the  horizon,  but  never  below  it. 

The  Oblique  Sphere.  All  people  on  the  earth,  excepting 
those  at  the  equator  and  the  poles,  have  this  position  of 
the  sphere.  In  this  case  the  horizon  cuts  the  equator  ob- 
liquely. To  place  the  globe  in  this  position,  elevate  the  pole 
to  the  latitude  of  the  place  of  the  observer.  Take  Boston, 
for  example,  and  elevate  the  north  pole  to  the  latitude  of 
Boston.  To  the  people  of  Boston,  for  six  months  of  the  year, 
the  days  are  more  than  12  hours  long,  and  for  the  other  six 
months  they  are  less  than  12  hours  long.  On  the  21st  of 
March  the  sun  shines  perpendicularly  over  the  equator,  and 
the  days  and  nights  are  equal  in  length  all  over  the  globe ; 
as  the  sun's  northern  declination  increases  the  days  increase 
in  length,  for  the  diurnal  arcs  described  by  the  sun  are  un- 
equally divided  by  the  horizon.     When  the  sun  has  attained 


joslin's  globes.  29 

its  greatest  northern  declination,  June  21,  the  days  have 
attained  their  greatest  length,  but  they  will  be  the  shortest 
to  the  people  of  the  southern  hemisphere.  After  this,  the 
sun's  northern  declination  gradually  decreases,  and  the  days 
also  decrease  in  length.  When  the  sun  arrives  at  the  autumnal 
equinox,  September  22,  the  days  and  nights  are  again  of 
equal  length.  After  this,  the  days  become  shorter  and  shorter 
as  the  sun's  southern  declination  increases,  until  it  has  at- 
tained its  greatest  southern  declination,  December  21.  Then 
the  days  will  be  shortest  with  us,  but  longest  to  the  people 
of  the  southern  hemisphere.  After  this,  our  days  increase  in 
length,  and,  when  the  sun  again  arrives  at  the  vernal  equinox, 
the  days  and  nights  are  again  equal. 

The  duration  of  twilight  is  greater  with  us  than  at  the 
equator,  because  with  us  the  diurnal  arc  of  the  sun  cuts  the 
horizon  obliquely,  which  causes  it  to  take  a  longer  time  to 
get  18°  below  the  horizon ;  whereas,  at  the  equator,  the  sun 
sinks  perpendicularly  below  the  horizon,  which  shortens  the 
duration  of  twilight. 

The  people  that  live  in  the  northern  hemisphere  can  never 
see  those  stars  which  lie  toward  the  south  polar  star,  and  the 
people  in  the  southern  hemisphere  can  never  see  those  stars 
which  lie  toward  the  north  polar  star ;  but,  as  already  noted, 
a  person  at  the  equator  may  see  all  the  stars  in  the  heavens 
in  the  course  of  the  year. 


30  joslin's  globes. 

THE   CELESTIAL  GLOBE. 

1.  The  Celestial  Globe  is  constructed  to  represent  the  aspect 
of  the  heavens ;  all  the  stars  are  laid  down  on  its  surface 
according  to  their  relative  situations ;  and  the  various  imagi- 
nary circles  and  points  upon  the  terrestrial  globe  are  sup- 
posed to  be  transferred  to  the  celestial  one.  The  rotary 
motion  of  this  globe,  from  east  to  west,  represents  the  apparent 
diurnal  motion  of  the  sun  and  stars  to  a  spectator  supposed 
to  be  situated  in  the  centre  of  the  globe. 

2.  The  Latitude  and  Longitude  of  a  Star  or  Planet.  The  lati- 
tude of  a  body  on  the  celestial  globe  is  its  distance  from  the 
ecliptic,  north  or  south,  measured  in  degrees  on  a  great 
circle  passing  through  the  body  and  the  pole  of  the  ecliptic ; 
and  the  longitude  is  the  distance  of  the  point,  where  the 
great  circle  cuts  the  ecliptic,  from  the  first  point  of  Aries. 
Latitude  and  longitude  are  referred  to  the  ecliptic  on  the 
celestial  globe,  but  on  the  terrestrial  globe  they  are  referred 
to  the  equator. 

3.  The  Declination  and  Eight  Ascension  of  a  heavenly  body. 
The  declination  of  a  body  is  its  distance  from  the  equinoctial, 
north  or  south,  measured  in  degrees  on  a  meridian  passing 
through  the  body ;  and  the  right  ascension  is  the  distance 
of  the  point  where  this  meridian  cuts  the  equinoctial,  from 
the  first  point  of  Aries.  The  right  ascension  of  a  body  is 
sometimes  expressed  in  hours,  making  the  usual  allowance  of 
one  hour  of  time  for  15°  of  distance. 

PEOBLEMS  ON  THE  CELESTIAL  GLOBE. 

Problem  I.  To  find  the  right  ascension  and  declination 
of  the  sun  or  of  a  star. 

Rule.  Bring  the  sun's  place  in  the  ecliptic,  or  the  given  star,  to  the 
metallic  meridian ;  the  degree  over  it  is  the  declination,  and  the  degree 
on  the  equator  cut  by  the  metallic  meridian  gives  the  right  ascension. 


joslin's  globes.  31 


EXAMPLES. 

1.   Required  the  right  ascension  and  declination  of  Regulus, 
in  the  constellation  of  the  Lion. 

Answer :    Right    ascension,    150° ;    Declination,    12°  47' 
north. 

Required  the  right  ascension  and  declination   of  the  fol- 
lowing stars :  — 

2.  Oapella,  in  the  constellation  of  Auriga. 

3.  Dubhe,  "  "  "         the  Great  Bear. 

4.  Aldebaran,  "  "  "         Taurus. 

5.  Arcturus,     "  "         Bootes. 

Answers : 

2.  Right  Ascension,  76°.         Declination,  45°  49'  north. 

3.  "  "        163°  15'.  "  62°  36'       " 

4.  "  "  66°.  "  16°  10'       " 

5.  "  "        212°.  "  20°    3'       " 


Problem  II.  The  right  ascension  and  declination  of  a 
heavenly  body  being  given,  to  find  its  place  on  the  globe. 

Rule.  Bring  the  given  degree  (or  given  time)  of  right  ascension  to 
the  metallic  meridian ;  then  under  the  given  degree  of  declination 
reckoned  on  the  metallic  meridian  you  will  find  the  place  of  the  body. 

EXAMPLES. 

1.  Required  the  star  whose  right  ascension  is  76°  45',  or 
5  hours  7  minutes,  and  declination  8°  24'  south. 

Answer :  Rigal,  a  star  of  the  first  magnitude  in  the  con- 
stellation of  Orion. 


32  joslin's  globes. 

What  stars  have  the  following  positions  ? 

Eight  Ascension.  Declination. 

2.  261°  30'  or  17  h.  26  min.         52°  25'  north. 

3.  6h.  38  min.         16°  29' south. 

4.  19  h.  43  min.  8°  26' north. 

5.  7  h.  35  min.         28°  26'  north. 
Answers  : 

2.  Alwaid,  in  the  constellation  of  Draco. 

3.  Sirius,  "  "  "  the  Great  Dog. 

4.  Al  Tair,       "  "  "  the  Eagle. 

5.  Pollux,         "  "  "  the  South  Twin. 

Problem  III.  To  find  the  latitude  and  longitude  of  any 
star. 

Rule.  Bring  the  pole  of  the  ecliptic  to  the  metallic  meridian ;  fix 
the  quadrant  of  altitude  over  the  pole,  and  move  the  quadrant  till  its 
edge  comes  over  the  star ;  then  the  degree  of  the  quadrant  over  the  star 
is  the  latitude,  and  the  number  of  degrees  between  the  edge  of  the  quad- 
rant and  the  first  point  of  Aries,  reckoned  on  the  ecliptic,  is  the  longitude. 

EXAMPLES. 

What  is  the  latitude  and  longitude  of  Aldebaran,  in  the 
constellation  of  Taurus. 

Answer:   Latitude,    5°  28'  'south.     Longitude,   2  signs, 
6°  53'. 

What  is  the  latitude  and  longitude  of  Pollux  in  Gemini  ? 
Answer :  Latitude,  6°  30'  north.    Longitude,  3  signs,  21°. 

Problem  IV.  The  day  and  hour  and  the  latitude  of  the 
place  being  given,  to  place  the  celestial  globe  so  as  to  represent 
the  appearance  of  the  heavens  at  that  place  and  time. 

Rule.  Rectify  the  globe  to  the  latitude  of  the  place ;  bring  the  sun's 
place  in  the  ecliptic  to  the  metallic  meridian  ;  set  the  hour  circle  to  12 


joslin's  globes.  33 

(recollect  this  is  12  noon) ;  turn  the  globe  till  the  hour  circle  points  to 
the  given  hour  of  the  day ;  then  in  this  position  the  stars  figured  on  the 
globe  will  exactly  correspond  with  the  actual  appearance  of  the  stars  in 
the  heavens. 


Problem  V.  The  day  and  hour  and  the  latitude  of  the 
place  being  given,  to  find  what  stars  are  rising,  setting,  and 
culminating. 

Rule.  Rectify  the  globe  for  the  latitude  of  the  place ;  bring  the 
sun's  place  in  the  ecliptic  to  the  metallic  meridian  ;  put  the  hour  circle 
to  12  noon  ;  turn  the  globe  till  the  hour  circle  indicates  the  given  hour 
of  the  day :  then  all  the  stars  on  the  eastern  semicircle  will  be  rising ; 
those  on  the  western  semicircle  will  be  setting ;  those  under  the  metallic 
meridian  will  be  culminating,  or  in  their  southing ;  and  the  stars  above 
the  wooden  horizon  will  be  visible  at  the  given  time  and  place. 

To  determine  those  stars  which  never  set.  Turn  the  globe  on  its  axis  ; 
then  those  stars  which  do  not  go  below  the  wooden  horizon  never  set  at 
the  given  place. 

EXAMPLES. 

To  find  the  constellations  which  are  rising,  setting,  and 
culminating,  on  January  20,  at  2  o'clock  in  the  morning,  at 
London. 

Answer:  The  constellations  of  Lyra,  etc.,  are  rising; 
Andromeda,  etc.,  are  setting;  and  the  Great  Bear,  etc., 
are  on  the  meridian. 

To  find  the  stars  which  are  rising,  setting,  and  culminating, 
on  the  8th  of  February,  at  9  o'clock  in  the  evening,  at 
London. 

Answer :  Alpheta,  in  the  Northern  Crown,  is  rising ; 
Arcturus,  in  Bootes,  is  a  little  above  the  horizon; 
Sirius  is  on  the  meridian;  Markab,  in  Pegasus,  is  just 
below  the  western  horizon. 


34 


Problem  VI.  To  find  the  time  when  any  star  will  rise, 
come  to  the  meridian,  and  set,  on  any  given  day,  at  any  given 
place. 

Rule.  Rectify  the  globe  to  the  latitude  of  the  place ;  bring  the 
sun's  place  in  the  ecliptic  to  the  metallic  meridian ;  set  the  hour  circle 
to  12  noon ;  turn  the  globe  till  the  given  star  comes  to  the  eastern  edge 
of  the  wooden  horizon  ;  then  the  hour  circle  will  show  the  time  of  rising: 
turn  the  globe  till  the  star  comes  to  the  metallic  meridian,  and  the  hour 
circle  will  show  the  time  of  its  culminating,  or  southing ;  turn  the  globe 
till  the  star  comes  to  the  western  edge  of  the  wooden  horizon,  and  the 
hour  circle  will  show  the  time  of  setting. 

EXAMPLES. 

At  what  time  will  Arcturus,  in  the  constellation  of  Bootes, 

rise,  culminate,  and  set,  at  London,  on  the  7th  of  September? 

Answer :  Arcturus  will  rise  at  7  o'clock  in  the  morning, 

culminate  at  3  o'clock  in  the  afternoon,  and  set  at  11 

o'clock  at  night. 

At    what    time   will    Aldebaran,    in   the    constellation    of 
Taurus,  rise,  culminate,  and  set,  at  Edinburgh,  on  Nov.  26  ? 
Answer:  Aldebaran  will  rise  at  4?  o'clock  in  the  after- 
noon, culminate  at  12£  o'clock  at  night,  and  set  at 
8  o'clock  the  next  morning. 

Problem  VII.  The  day  of  the  month,  the  latitude  of  the 
place,  and  the  altitude  of  a  star  being  given,  to  find  the  hour 
of  the  night. 

Rule.  Rectify  the  globe  to  the  latitude  of  the  place  ;  bring  the  sun's 
place  in  the  ecliptic  to  the  metallic  meridian  ;  set  the  hour  circle  to  12 
noon ;  screw  the  quadrant  of  altitude  to  the  zenith,  and  turn  it  to  that 
side  of  the  meridian  on  which  the  star  was  observed ;  move  the  globe 
and  the  quadrant  till  the  star  is  on  the  degree  of  the  quadrant  equal  to 
the  given  altitude ;  then  the  hour  circle  will  show  the  hour  required. 


joslin's  globes.  35 

EXAMPLES. 

At  Rome,  on  December  2,  the  star  Capella,  in  the  con- 
stellation of  Auriga,  was  observed  to  be  42°  above  the  horizon ; 
required  the  hour. 

Answer :  5  o'clock  in  the  morning. 

At  London,  on  December  29,  the  star  Deneb,  in  the  tail  of 
the  Lion,  was  found  to  be  40°  above  the  horizon  and  east  of 
the  meridian  ;  required  the  hour. 

Answer :  About  2.15  o'clock  in  the  morning. 


Problem  VIII.  Given  the  year  and  the  day,  to  find  the 
place  of  a  planet  on  the  globe. 

Rule.  Bring  the  sun's  place  in  the  ecliptic  to  the  metallic  meridian  ; 
set  the  hour  circle  to  12  noon  ;  find  in  the  Nautical  Almanac  the  time 
when  the  planet  passes  the  meridian  on  the  given  day,  and  turn  the 
globe  till  the  index  of  the  hour  circle  points  to  the  hour  thus  found ; 
find  in  the  Almanac  the  declination  of  the  planet  for  the  same  day ; 
then,  under  this  declination,  found  on  the  metallic  meridian,  is  the  place 
of  the  planet. 


36 


JOSLINS    GLOBES. 


Style  3. 

Joslin's  Bronze  Pedestal  Stand. 


joslin's  globes.  37 


JOSLIN'S    BRONZE    PEDESTAL    STAND. 


Style  3. 

Mounted  in  this  manner,  the  globe  is  brought  to  a  con- 
venient height  for  use  while  sitting,  and,  at  the  same  time, 
presents  an  ornamental  appearance,  adapting  it  to  the  parlor 
and  library  as  well  as  to  the  school-room.  It  is  furnished 
with  horizon,  graduated  full  brass  nickel-plated  meridian, 
hour  dial,  etc. 

The  stand  is  of  bronzed  iron,  and  of  such  design  as  to  com- 
bine great  strength  with  light  weight  and  symmetrical  ap- 
pearance. Being  mounted  upon  brass  castors,  can  be  readily 
moved  to  any  position. 

PRICES. 

18-inch  Globe,  43  inches  high        .         .         .  §80.00 

16    "         "       42£    "  ...     62.50 

12    "         "       381    "     .  ■"  ...     37.50 

Globe  with  Celestial  Map,  same  price. 


-y\    JG/vi£jt/?    c>1    aXX  3/- 


38 


JOSLIN  S    GLOBES. 


Style  6. 

Joslin's  Tripod  Stand. 


joslin's  globes.  39 


JOSLIN'S    TRIPOD    STAND. 


Style  6. 

This  style  of  mounting  was  gotten  up  particularly  for 
parlor  and  library  use,  many  persons  objecting  to  an  iron 
stand.  It  makes  a  very  light,  strong,  and  ornamental  stand, 
and  will  look  well  with  any  furniture.  The  arms  that  sup- 
port the  ball  and  horizon  are  japanned  and  decorated,  and 
pivoted  the  same  as  in  all  rotary  globes.  The  legs  are 
japanned  with  a  little  decorating,  and  screw  into  the  socket 
supporting  the  arms  by  a  polished  brass  cap-piece  fastened 
to  their  top. 

PRICES. 

18-inch  Globe $78.00 

16  "        60.00 

12  "        37.50 

Globe  with  Celestial  Map,  same  price. 


40 


JOSLIN  S    GLOBES. 


JOSLIN'S    LOW    BRONZE    STAND. 


Style  4. 


This  style,  with  black  walnut  horizon,  graduated  full  brass 
meridian,  hour  dial,  etc.,  is  mounted  upon  a  light  bronzed 
stand  of  neat  and  appropriate  design. 

The  arms  which  support  the  horizon  are  pivoted  to  the 
base,  thus  allowing  any  portion  of  the  globe  to  be  turned  to 
the  student  without  changing  the  position  of  the  base  itself, 
a  very  desirable  arrangement. 


PRICES. 


16-inch  Globe 
12    " 
10    " 


00 
25.00 
18.00 


Globe  with  Celestial  Map,  same  price. 


JOSLINS    GLOBES. 


41 


JOSLIN'S    FULL    WOOD    STAND. 


Style  5. 


Mounted  upon  a  substantially  made  cherry  wood  stand, 
with  horizon,  graduated  full  brass  meridian,  hour  dial,  and 
index,  this  globe  has  all  the  appliances  for  use  in  the  solution 
of  problems.     It  is  well  adapted  to  all  grades  of  schools. 


PRICES. 

16-inch  Globe $45.00 

12    "  22.00 

10    "  17.00 

6    "         "  .         .         .         .         .         .     10.00 

Globe  with  Celestial  Map,  same  price. 


42  joslin's  globes. 


JOSLIN'S    LOW   TRIPOD   STAND. 


Style  8. 


Mounted  upon  three  light,  neat,  bronzed  iron  legs  (prevent- 
ing any  shrinking  and  coming  apart,  as  sometimes  happens  in 
wooden  stands),  with  black  walnut  horizon,  graduated  full 
brass  meridian,  hour  dial,  and  index.  Everything  is  as  accu- 
rate as  in  the  highest  priced  globe  ever  made. 

PRICES. 

12-inch  Globe $22.00 

10   "  17.00 

Globe  with  Celestial  Map,  same  price. 


JOSLINS    GLOBES. 


43 


JOSLIN'S   SEMI-CIRCLE    STAND. 


Style  1. 


Polished  black  walnut  stand,  with  graduated  brass  semi- 
meridian.  For  those  who  use  the  globe  for  reference  only,  and 
who  never  desire  to  work  problems,  this  style  is  neat  and  most 
appropriate. 

PRICES. 

12-inch  Globe $17.00 

10    "  12.00 

6    "        " 5.00 

Globe  with  Celestial  Map,  same  price. 


44 


JOSLINS    GLOBES. 


JOSLIN'S    TELLURIC    GLOBE. 


This  style  was  specially  designed  to  furnish  a  simple  means 
of  illustrating  the  causes  of  the  Changes  of  the  Seasons  and  of 
the  numerous  other  phenomena  which  are  related  to  them. 
Their  success  in  accomplishing  this  much  desired  end  is  fully 
attested  by  the  high  commendations  of  teachers  from  all 
sections  of  the  country. 

Each  globe  is  accompanied  with  a  printed  manual  of  30 
pages,  giving  a  complete  description  of  the  globe  and  its 
various  uses,  with  illustrative  problems. 


PRICE. 


6-inch  Globe 


.  $15.00 


PAMPHLET  BINDERS 

This  is  No,        1525 

also  carried  in  stock  in  the  following  sizes 

HIGH  WIDE     THICKNESS 

1529  12    inches  10    inches     H  inch 

1530  12  "      9H      " 

1932  13  "     10 

1933  14  "    11 

1934  10         "    12 


HIGH  WIDE      THfCKNESS 

1523  9     inches  7    inches     /i  inch 

1524  10        "  7  " 

1525  9        "  6 

1526  9M    "  1Ys     " 

1527  103^    "  7H     " 

1528  11        "  8 

Other  sizes  made  to  order 


MANUFACTURED  BY 

LIBRARY  BUREAU 

Division  of  REMINGTON  RAND  INC. 

Library  Supplies  of  all  kinds 


SMITHSONIAN  INSTITUTION  LIBRARIES 

3   9088   00769   8129